part 6

(1876).

Fraser of Edinburgh (about 1863 or earlier) discovered the specific power of the seed in contracting the pupil, when the alcoholic extract is applied to the eye. These myotic effects, counteracting those of atropine and hyoscyamine, were further examined by many other experimenters on mammals or birds. The action of the poison when taken internally was found rapidly to affect the cardiac contractions and finally to paralyze the heart.

=Description=—The fruit of _Physostigma_ is a dehiscent, oblong legume about 7 inches in length, containing 2 or 3 seeds. The latter, commonly known as _Calabar Beans_, are 1 to 1⅜ inches long, about ⁶/₈ of an inch broad, and ⁴/₈ to ⅝ of an inch in thickness, weighing on an average twenty seeds, 67 grains each.

They have an oblong, subreniform outline, one side being straight or but slightly incurved, the other boldly arched. The latter is marked by a broad furrow, ⅛ of an inch wide, bordered with raised edges, and running from the micropyle, which is a small funnel-shaped depression, quite round the opposite end of the seed. In the middle of this remarkable furrow the raphe is seen as a long raised suture running from end to end. The surface of the seed is somewhat rough, but has a dull polish; it is of a deep chocolate-brown, passing into a lighter tint on the ridges bordering the furrow. The latter is black, dull, and finely rugose.

When the seed is broken the cotyledons are found adherent to the testa, with a large cavity between them. The air thus included causes the seeds to float on water, but they sink immediately when broken. After digestion for some hours in warm water, the testa having been previously cracked, the whole seed softens and swells so that its structure may be easily studied. Each cotyledon is then seen to be marked on the hilum-side by a long shallow furrow, at one end of which, just below the micropyle, lies the plumule and radicle. A dark brown inner membrane, constituting part of the testa, surrounds the cotyledons.

The seeds have scarcely any taste, or not more than an ordinary bean; nor in the dry state have they any odour. After being boiled, or when their alcoholic tincture is evaporated, an odour suggesting cantharides is developed.

=Microscopic Structure=—The cotyledons are built up of large globular or ovoid cells, those of the outermost layer being smaller and of rather cubic form. This parenchyme is loaded with starch granules, frequently as much as 50 mkm. in diameter. Their interior part is less distinctly stratified than the outer; the hollow centre radiates in various directions around the axis of the ovate granule. Polarized light does not show a cross as in other more globular starch granules, but two elliptic curves approaching one another near the axis of the granule. Similar starch granules are commonly met with in the seeds of _Leguminosæ_.

In the Calabar seeds the starch is accompanied by numerous particles of albuminous matter becoming distinctly perceptible by addition of iodine, which imparts to them an orange colouration.

The shell of the seed is built up of four different layers; the prevailing layer consists of very long, simply cylindrical cells, densely packed so as to form only one radial row. Tison[760] has endeavoured to ascertain in what region of the seed the active principle is lodged; and he has arrived at the conclusion that its seat is the granular protoplasmic particles, which alone acquire an orange tint by the action of weak caustic alkalis.

[760] _Histoire de la Fève de Calabar_, Paris, 1873. 38.

=Chemical Composition=—Jobst and Hesse[761] proved in 1863 that the poisonous nature of Calabar bean depends upon an alkaloid, to which they gave the name _Physostigmine_. It is obtained by the method generally adopted for extracting analogous substances, that is, by precipitating one of its salts from an aqueous solution by bicarbonate of sodium, and dissolving out the base with ether or benzol. As extracted by these chemists, physostigmine is an amorphous mass of decidedly alkaline reaction, soluble in much water and in acids. On exposure to the air the solution soon becomes red, or sometimes intensely blue, a partial decomposition of the alkaloid taking place. The red coloration may even be observed in the aqueous infusion of a few cotyledons. It disappears by sulphuretted hydrogen or sulphurous acid, but returns if these reducing agents are allowed to evaporate.

Hesse[762] ascertained (1867) that physostigmine consists of C₃₀H₂₁N₃O₄; he now obtained it perfectly colourless and tasteless, softening at 40° C., fusing at 45°, but not supporting a heat of 100° C., without decomposition, which is manifested by a red coloration.

In 1865 Vée and Leven,[763] by treating the powdered unpeeled seed in nearly the same way, prepared an alkaloid which they called _Eserine_. It differs from Hesse’s physostigmine in that it forms colourless, rhomboidal, tabular crystals of a bitter taste, melting at 90° C. It dissolves easily in ether, alcohol, or chloroform, but very sparingly in water. The last named solution is alkaline, and reddens by exposure to the air.

It is assumed by some writers, as Tison,[764] that eserine is only the pure form of physostigmine; but at present we feel hardly warranted in admitting the identity of the two substances.

Harnack and Witkowski in 1876 ascertained the presence of another alkaloid in the seed, which they called _Calabarine_. It is nearly insoluble in ether and also very different from physostigmine in its physiological action, but somewhat similar to strychnine. Calabarine is consequently not to be found in those preparations of calabar bean which have been obtained or purified by means of ether.

Hesse (1878) exhausted the cotyledons of Physostigma with petroleum ether, and obtained crystals of a new indifferent substance C₂₆H₄₄+OH₂, which he called _Phytosterin_. It is closely allied to Cholesterin, but, in its solution in chloroform, devoid of rotatory power and melting at 133°. Cholesterin melts at 145°, and deviates, in its ethereal solution, the ray of polarized light to the left. Phytosterin also occurs in peas; Hesse suggests that the crystallized appearance of alkaloids as prepared by former observers was perhaps due to phytosterin.

From the cotyledons _per se_, cold water extracts mucilage, precipitable by neutral acetate of lead. The watery infusion contains also albumin, which may be coagulated by heat or by alcohol. The infusion is colourless, does not redden litmus, nor does it contain sugar in appreciable proportion; a few drops of solution of potash cause it to assume an orange colour. An infusion of the shell of the seed is already of this colour, but the tint is intensified by caustic alkali.

[761] Liebig’s _Annalen der Chem. u. Pharm._ 129 (1864) 115.

[762] _Ibid._ 141 (1867) 82; _Chem. News_, 22 March 1867, 149.

[763] _Comptes Rendus_, lx. (1865) 1194.

[764] _Op. cit._ chap. 2.

The cotyledons yield to boiling ether ½ to ⅓ per cent. of fatty oil, and after exhaustion by ether and alcohol, afford to cold water 12 per cent. of albuminous and mucilaginous constituents. The proportion of starch according to Teich[765] amounts to 48 per cent., the albuminous matter to 23 per cent. The entire seed furnishes 3 per cent. of ash, chiefly phosphate of potash. These constituents do not widely differ in proportion from those found in the common bean, which yields 23 to 25 per cent. of albuminous matters, and 32 to 38 per cent. of starch, besides 1 to 3 per cent. of oil.

[765] _Chemische Untersuchung der Calabarbohne_.—Inauguralschrift, St. Petersburg, 1867. We calculate the albuminous matters with reference to _Teich’s_ analysis, which proved the kernels to contain 3·65 per cent. of nitrogen.

The shells of Calabar bean are stated by Fraser to be by no means devoid of active principle.

Vée asserts that if to a solution of eserine, a little potash, lime, or carbonate of sodium be added, there is developed a red colour which rapidly increases in intensity. This colour is transient, passing into yellow, green and blue. If chloroform is shaken with such coloured solution, it takes up the colour; ether on the other hand remains uncoloured.

=Uses=—Calabar has been hitherto chiefly employed as an ophthalmic medicine, for the purpose of contracting the pupil. It has however been occasionally administered in tetanus and in neuralgic, rheumatic, and other diseases.

=Adulteration=—Other seeds are sometimes fraudulently mixed with Calabar beans. We have noticed in particular those of a _Mucuna_ and of the Oil Palm, _Elæis guineensis_ Jacq. The slightest examination suffices for their detection.

KINO.

_Kino_, _Gum Kino_, _East Indian Kino_; F. and G. _Kino_.

=Botanical Origin=—_Pterocarpus Marsupium_ Roxb., a handsome tree 40 to 80 feet high, frequent in the central and southern parts of the Indian Peninsula and also in Ceylon, and affording a valuable timber. In the Government forests of the Madras Presidency, it is one of the _reserved trees_, the felling of which is placed under restrictions.

_Pt. indicus_ Willd., a tree of Southern India, the Malayan Peninsula and the Indian and Philippine Islands, is capable of yielding kino, and is the source of the small supplies of that drug that were formerly shipped from Moulmein.

Several other plants afford substances bearing the name of _Kino_, which will be noticed at the conclusion of the present article.

=History=—The introduction of kino into European medicine is due to Fothergill, an eminent physician and patron of economic botany of the last century. The drug which Fothergill examined was brought from the river Gambia in West Africa as a rare sort of Dragon’s Blood, and was described by him in 1757[766] under the name of _Gummi rubrum astringens Gambiense_. It had been noticed at least twenty years before as a production of the Gambia, by Moore, factor to the Royal African Company, who says that the tree yielding it is called in the Mandingo language _Kano_.[767] Specimens of this tree were sent to England in 1805 by the celebrated traveller Mungo Park, and recognized some years later as identical with the _Pterocarpus erinaceus_ of Poiret.

It seems probable that African kino continued to reach England for some years, for we find “_Gummi rubrum astringens_” regularly valued in the stock of a London druggist[768] from 1776 to 1792.

Duncan in the _Edinburgh Dispensatory_ of 1803, while asserting that “_kino is brought to us from Africa_,” admits that some, not distinguishable from it, is imported from Jamaica. In a later edition of the same work (1811), he says that the African drug is no longer to be met with, and alludes to its place being supplied by other kinds, as that of Jamaica, that imported by the East India Company, and that of New South Wales derived from _Eucalyptus resinifera_ Sm. It will thus be seen that at the commencement of the present century several substances, produced in widely distant regions, bore the name of _Kino_. That however which was principally used in the place of the old African drug, was _East Indian_ Kino, the botanical origin of which was shown by Wight and by Royle[769] (1844-46) to be _Pterocarpus Marsupium_ Roxb.,—a tree which, curiously enough, is closely allied to the kino tree of Tropical Africa.

This is the drug which is recognized as legitimate kino in all the principal pharmacopœias of Europe. It appears to have been first prepared for the European market in the early part of the present century, on a plantation of the East India Company called Anjarakandy, a few miles from Tellicherry on the Malabar Coast; but as we learn from our friend Dr. Cleghorn, it was not grown there but on the ghats a short distance inland.

=Extraction=—Kino is the juice of the tree, dried without artificial heat.[770] As it exudes, it has the appearance of red currant jelly, but hardens in a few hours after exposure to the air. In the Government forests of the Malabar Coast whence the supplies are obtained, permission to collect the drug is granted on payment of a small fee, and on the understanding that the tapping is performed skilfully and without damage to the timber. The method pursued is this:—A perpendicular incision with lateral ones leading into it, is made in the trunk, at the foot of which is placed a vessel to receive the outflowing juice. This juice soon thickens, and when sufficiently dried by exposure to the sun and air, is packed into wooden boxes for exportation.

=Description=—Malabar kino[771] consists of dark, blackish-red, angular fragments rarely larger than a pea, easily splitting into still smaller pieces, which are seen to be perfectly transparent, of a bright garnet hue, and amorphous under the microscope. In cold water they sink, but partially dissolve by agitation, forming a solution of very astringent taste, and a pale flocky residue. The latter is taken up when the liquid is made to boil, and deposited on cooling in a more voluminous form. Kino dissolves almost entirely in spirit of wine (·838), affording a dark reddish solution, acid to litmus paper, which by long keeping sometimes assumes a gelatinous condition. It is readily soluble in solution of caustic alkali, and to a large extent in a saturated solution of sugar.

[766] _Medical Observations and Inquiries_, i. (1757) 358.

[767] _Travels into the Inland Parts of Africa_, by Francis Moore, Lond. 1737. pp. 160. 209. 267.

[768] J. Gurney Bevan, Plough Court, Lombard Street.—The drug was priced in 1787 as having cost 16_s._, and in 1790-92, 21_s._ per lb.

[769] _Pharm. Journ._ v. (1846) 495.

[770] Cleghorn, _Forests and Gardens of South India_, 1861. 13.—Also from information communicated by him orally.

[771] Our sample obtained from _Pt. Marsupium_ Roxb. on the Sigúr Ghat, Feb. 1868, was kindly submitted to us by Mr. McIvor of Ootacamund.—We find it to agree with commercial East Indian Kino.

=Chemical Composition=—Cold water forms with kino a reddish solution, which is at first not altered if a fragment of ferrous sulphate is added. But a violet colour is produced as soon as the liquid is cautiously neutralized. This can be done by diluting it with common water (containing bicarbonate of calcium) or by adding a drop of solution of acetate of potassium. Yet the fact of kino developing an intense violet colour in presence of a proto-salt of iron, may most evidently be shown by shaking it with water, and iron reduced by hydrogen. The filtered liquid is of a brilliant violet, and may be evaporated at 100° without turning green; the dried residue even again forms a violet solution with water. By long keeping the violet liquid gelatinizes. It is decolorized by acids, and turns red on addition of an alkali, whether caustic or bicarbonated. Catechu, as well as crystallized catechin, show the same behaviour, but these solutions quickly turn green on exposure to air.

Solutions of acids, of metallic salts, or of chromates produce copious precipitates in an aqueous solution of kino. Ferric chloride forms a dirty green precipitate, and is at the same time reduced to a ferrous salt. Dilute mineral acids or alkalis do not occasion any decided change of colour, but the former give rise to light brownish-red precipitates of _Kino-tannic Acid_. By boiling for some time an aqueous solution of kino-tannic acid, a red precipitate, _Kino-red_, is separated.

Kino in its general behaviour is closely allied to Pegu catechu, and yields by similar treatment the same products, that is to say, it affords _Pyrocatechin_ when submitted to dry distillation, and _Protocatechuic Acid_ together with _Phloroglucin_ when melted with caustic soda or potash.

Yet in catechu the tannic acid is accompanied by a considerable amount of catechin, which may be removed directly by exhaustion with ether. Kino, on the other hand, yields to ether only a minute percentage of a substance, whose scaly crystals display under the microscope the character of _Pyrocatechin_, rather than that of catechin, which crystallizes in prisms. The crystals extracted from kino dissolve freely in cold water, which is not the case with catechin, and this solution assumes a fine green if a very dilute solution of ferric chloride is added, and turns red on addition of an alkali. This is the behaviour of catechin as well as of pyrocatechin; but the difference in solubility speaks in favour of the crystals afforded by kino being pyrocatechin rather than catechin.

We thought pyrocatechin must also occur in the mother plant of kino, but this does not prove to be the case, no indication of its presence being perceptible either in the fresh bark or wood.[772]

Etti (1878) extracted from kino colourless prisms of _Kinoïn_ by boiling the drug with twice its weight of hydrochloric acid, about 1·03 sp. gr. On cooling, kino-red separates, very little of it remaining in solution together with kinoïn. The latter is extracted by exhausting the liquid with ether, which by evaporation affords crystals of kinoïn. They should be recrystallized from boiling water; they agree with the formula C₁₄H₁₂O₆, which is to be regarded as that of a methylated gallic ether of pyrocatechin, viz., C₆H₄ (OCH₃) C₇H₅O₅.

Kinoïn by heating it to 130° C. gives off water and turns red:

2 C₁₄H₁₂O₆ = OH₂ · C₂₈H₂₂O₁₁.

The latter product is an amorphous mass agreeing with kino-red; by heating it at 160-170° it again loses water, thus affording another anhydride.

Etti succeeded in preparing methylic chloride, pyrocatechin CH₄(OH)₂ as well as gallic acid C₇H₆O₅, by decomposing kinoïn.

We have prepared kinoïn from _Australian kino_ (see page 198), but failed in obtaining it from Malabar kino, which however Etti states to have used. Kino affords about 1½ per cent. of kinoïn.

The solutions of kinoïn turn red on addition of ferric salts.

Commercial kino yielded us 1·3 per cent. of ash.

=Commerce=—The quantity of true kino collected in the Madras forests is comparatively small, probably not exceeding a ton or two annually. The drug is often shipped from Cochin.

=Uses=—Kino is administered as an astringent. It is said to be used in the manufacture of wines, and it might be employed if cheap enough in tanning and dyeing.

Other sorts of Kino.

1. _Butea Kino_, _Butea Gum_, _Bengal Kino_, _Palas or Pulas Kino_, _Gum of the Palas or Dhak Tree_.

This is an exudation from _Butea frondosa_ Roxb. (_Leguminosæ_), a tree of India and Burma, well known under the name of _Palas_ or _Dhak_, and conspicuous for its splendid, large, orange, papilionaceous flowers.[773] According to Roxburgh it flows during the hot season from natural fissures or from wounds made in the bark, as a red juice which soon hardens into a ruby-coloured, brittle, astringent gum.

[772] We have to thank Mr. Broughton, late of the Cinchona Plantations, Ootacamund, for determining this point. In the bark almost saturated with fresh liquid kino, he utterly failed to obtain any indication of pyrocatechin by the tests which he found to render it easily evident in dry kino.

[773] See Nees von Esenbeck, _Plantæ medicinales_, Düsseldorf, iii. (1833) tab. 79.

Authentic specimens of this kino have been placed at our disposal by Mr. Moodeen Sheriff of Madras and by Dr. J. Newton of Bellary. That received from the first-named gentleman consists of flattish, angular fragments (the largest about ½ an inch across) and small drops or tears of a very dark, ruby-coloured gum, which when held to the light is seen to be perfectly transparent. The flat pieces have been mostly dried on leaves, an impression of the veins of which they retain on one side, while the other is smooth and shining. The substance has a pure astringent taste, but no odour. It yielded us 1·8 per cent. of ash and contained 13·5 per cent. of water. Ether removes from it a small quantity of _pyrocatechin_. Boiling alcohol dissolves this kino to the extent of 46 per cent.; the solution which is but little coloured, produces an abundant greyish-green precipitate with perchloride of iron, and a white one with acetate of lead. It may be hence inferred that a tannic acid, probably kino-tannic acid, constitutes about half the weight of the drug, the remainder of which is formed of a soluble mucilaginous substance which we have not isolated in a state of purity. By submitting the Butea kino of Mr. Moodeen Sheriff to dry distillation we obtained pyrocatechin.

The sample from Dr. Newton is wholly in transparent drops and stalactitic pieces, considerably paler than that just described, but of the same beautiful ruby tint. The fragments dissolve freely and almost completely in cold water, the solution being neutral and exhibiting the same reactions as the former sample.

Butea kino, which in India is used in the place of Malabar kino, was long confounded with the latter by European pharmacologists, though the Indian names of the two substances are quite different. It is not obtained exclusively from _B. frondosa_, the allied _B. superba_ Roxb. and _B. parviflora_ Roxb. affording a similar exudation.

2. _African or Gambia Kino._—Of this substance we have a specimen collected by Daniell[774] in the very locality whence it was obtained by Moore in 1733 (see p. 195), and by Park at the commencement of the present century. The tree yielding it, which still bears the Mandingo name _Kano_, and grows to a height of 40 to 50 feet, is _Pterocarpus erinaceus_ Poiret, a native of Tropical Western Africa from Senegambia to Angola. The juices exude naturally from crevices in the bark, but much more plentifully by incisions; it soon coagulates, becoming deep blood-red and remarkably brittle. That in our possession is in very small, shining, angular fragments, which in a proper light appear transparent and of a deep ruby colour. In solubility and chemical characters, we can trace no difference between it and the kino of the allied _Pt. Marsupium_ Roxb. This kino does not now find its way to England as a regular article of trade. From the statement of Welwitsch, it appears that the Portuguese of Angola employ it under the name of _Sangue de Drago_.[775]

3. _Australian, Botany Bay, or Eucalyptus Kino._—For some years past, the London drug market has been supplied with considerable quantities of kino from Australia; in fact at one period this kino was the only sort to be purchased.

[774] See his paper _On the Kino Tree of West Africa, Pharm. Journ._ xiv. (1855) 55.

[775] _Madeiras e Drogas medicinaes de Angola_, Lisboa, 1862, 37.

As it is the produce of numerous species of _Eucalyptus_, it is not surprising that it presents considerable diversity of appearance. The better qualities closely agree with Pterocarpus kino. They are in dark reddish-brown masses or grains, which when in thin fragments are seen to be transparent, of a garnet red hue and quite amorphous. The substance is mostly collected by the sawyers and wood-splitters. It is found within the trunks of trees of all sizes, in flattened cavities of the otherwise solid wood which are often parallel to the annual rings. In such place the kino, which is at first a viscid liquid, becomes inspissated and subsequently hard and brittle. It may also be obtained in a liquid state by incisions in the stems of growing trees: such liquid kino has occasionally been brought into the London market; it is a viscid treacle-like fluid, yielding by evaporation about 35 per cent. of solid kino.[776]

Authentic specimens of the kino of 16 species of _Eucalyptus_ sent from Australia by F. von Müller, have been examined by Wiesner of Vienna.[777] He found the drug to be in most cases readily soluble in water or in spirit of wine, the solution being of a very astringent taste. The solution gave with sulphuric acid a pale red, flocculent precipitate of _Kino-tannic Acid_; with perchloride of iron (as in common kino) a dusky greenish precipitate,—except in the case of the kino of _E. obliqua_ L’Hér. (Stringy-bark Tree), the solution of which was coloured dark violet.

Wiesner further states, that Eucalyptus kino affords a little _Catechin_[778] and _Pyrocatechin_. It contains no pectinous matter, but in some varieties a gum-like that of _Acacia_. In one sort, the kino of _E. gigantea_ Hook,[779] gum is so abundant that the drug is nearly insoluble in spirit of wine.

By Etti’s process, as given at page 197, we obtained kinoïn from an Australian Kino, which contained numerous fragments of the wood. We noticed that both Australian and Malabar kino emitted a somewhat balsamic odour, when they were treated with hydrochloric acid.

From this examination, it is evident that the better varieties of Eucalyptus kino, such for instance as those derived from _E. rostrata_ Schlecht. (_Red_ or _White Gum_, or _Flooded Gum_ of the colonists), _E. corymbosa_ Sm. (_Blood-wood_) and _E. citriodora_ Hook., possess the properties of Pterocarpus kino and might with no disadvantage be substituted for it.

[776] Victoria Exhibition, 1861.—Jurors’ Report on Class 3. p. 59.

[777] _Zeitschrift des österreich. Apotheker-Vereines_ ix. (1871) 497; _Pharm. Journ._ Aug. 5, 1871. 102.

[778] In our opinion this is doubtful.

[779] Bentham unites this species to _E. obliqua_ L’Hér (_Flor. Austr._ iii. 204).

LIGNUM PTEROCARPI.

_Lignum Santalinum rubrum_, _Santalum rubrum_; _Red Sanders Wood_, _Ruby Wood_; F. _Bois de Santal rouge_; G. _Rothes Sandelholz_, _Caliaturholz_.

=Botanical Origin=—_Pterocarpus santalinus_ Linn. fil.—A small tree not often exceeding 3½ to 4 feet in girth, and 20 to 25 feet in height; it is closely related to _Pt. Marsupium_ Roxb., from which it differs chiefly in having broader leaflets always in threes. It is a native of the southern part of the Indian Peninsula, as Canara, Mysore, Travancore and the Coromandel Coast, but also occurs in Mindanao, in the southern Philippines. In India the districts in which the wood is at present chiefly obtained are the forests of the southern portion of the Kurnool Hills, Cuddapah and North Arcot (W. and N.W. of Madras). The tree is now being raised in regular plantations.[780]

The wood is a staple article of produce, and the felling of the trees is strictly controlled by the forest inspectors. The fine trunk-wood is highly valued by the natives for pillars in their temples and other buildings, as well as for turnery. The stumps and roots are exported to Europe as a dye-stuff, mostly from Madras.

=History=—It is difficult to tell whether the appellation _Red_ Sandal-wood used in connexion with _Yellow_ and _White_ Sandal-wood by some of the earlier writers on drugs, was intended to indicate the inodorous dyewood under notice or the aromatic wood of a species of _Santalum_. Yet when Marco Polo[781] alludes to the sandal-wood imported into China, and to the _red_ sandal (“_Cendal vermeil_”) which grows in the island of Necuveran (Nicobar), it is impossible to doubt that he intended by this latter name some such substance as that under notice.

Garcia de Orta, who wrote at Goa in the middle of the 16th century, clearly distinguished the fragrant sandal of Timor from the red inodorous wood of Tenasserim and the Coromandel Coast. It is remarkable that the wood of _Pt. santalinus_ is distinguished to the present day in all the languages of India by names signifying _red-coloured sandal-wood_, though it has none whatever of the peculiarities of the odorous wood of _Santalum_. Red Sanders Wood was formerly supposed to possess medicinal powers: these are now disregarded, and it is retained in use only as a colouring agent.

During the middle ages, it was used as well as alkanet for culinary purposes, such as the colouring of sauces and other articles of food. The price in England between 1326 and 1399 was very variable, but on an average exceeded 3_s._ per lb.[782] Many entries for the purchase of Red Sanders along with spices and groceries, occur in the accounts of the Monastery of Durham, A.D. 1530-34.[783]

=Description=—The wood found in English commerce is mostly that of the lower parts of the stem and that of the thickest roots. It appears in the market in ponderous, irregular logs, rarely exceeding the thickness of a man’s thigh and commonly much smaller, 3, 4 or 5 feet in length; they are without bark or sapwood, and are externally of a dark colour. The internal wood is of a deep, rich, blood-red, exhibiting in transverse section zones of a lighter tint, and taking a fine polish.

At the present day, druggists generally buy the wood rasped into small chips, which are of a deep reddish-brown hue, tasteless and nearly without odour.

[780] (Beddome), _Report of the Conservator of Forests_, for 1869-70, Madras, 1870, pp. 3. 39. 123; for figure of the tree, see _Flora Sylvatica of Southern India_ of the same author, tab. xxii.

[781] Pauthier, _Livre de Marco Polo_, 580—_Pt. indicus_ Willd. grows in the adjacent Andaman Islands.

[782] Rogers, _Agriculture and Prices in England_, 1866, i. 631, ii. 545, &c.—The average price of a sheep during the same period was about 1_s._ 6_d._

[783] _Durham Household Book_, Surtees Soc. 1844. 215; also Pegge, _Form of Cury_, Lond. 1780. p. xv.

=Microscopic Structure=—The wood is built up for the greater part of long pointed cells, having thick walls (libriform). Through this ligneous tissue, there are scattered small groups of very large vessels. In a direction parallel to the circumference of the stem, there are less coloured small parenchymatous layers, running from one vascular bundle to another. The whole tissue is finally traversed by very narrow medullary rays, which are scarcely perceptible to the unaided eye. The parenchymatous cells are each loaded with one crystal of oxalate of calcium, which are so large that, in a piece of the wood broken longitudinally, they may be distinguished without a lens. The colouring matter is contained especially in the walls of the vessels and the ligneous cells.

=Chemical Composition=—Cold water or fatty oil (almond or olive) abstracts scarcely anything from the wood, and hot water but very little. On the other hand, ether, spirit of wine, alkaline solutions, or concentrated acetic acid, readily dissolves out the colouring matter. Essential oils of bitter almond or clove take up a good deal of the red substance; that of turpentine none at all. This resinoid substance, termed _Santalic Acid_ or _Santalin_,[784] is said to form microscopic prismatic crystals of a fine ruby colour, devoid of odour and taste, fusing at 104° C., insoluble in water but neutralizing alkalis and forming with them uncrystallizable salts.

Weidel (1870) exhausted the wood with boiling water, containing a little potash, and obtained by means of hydrochloric acid a red precipitate, which was redissolved in boiling alcohol and then furnished _colourless_ crystals of _Santal_, C₈H₆O₃. They are devoid of odour or taste, not soluble in water, benzol, chloroform, bisulphide of carbon, and but sparingly in ether. Santal yields with potash a faintly yellow solution which soon turns red and green. The wood afforded Weidel not more than 3 per mille of santal.

Cazeneuve (1874)[785] mixed 4 parts of the wood with 1 part of slaked lime, and exhausted the dried powder with ether containing a little alcohol. After the evaporation of the ether, a small amount of colourless crystals of _Pterocarpin_ was obtained, which were purified by recrystallization from boiling alcohol. They melt at 83° C., and are abundantly soluble in chloroform, in bisulphide of carbon, very little in cold alcohol, not at all in water. Pterocarpin agrees with the formula C₁₇H₁₆O₅. It yields a red solution with concentrated sulphuric acid, and a green with nitric acid 1·4 sp. gr. By submitting it to destructive distillation pyrocatechin appears to be formed.

Franchimont (1879) assigns the formula C₁₇H₁₆O₆ to another principle of Red Sanders Wood, which he isolated by means of alcohol. It is an amorphous substance, melting at 105°. By extracting the wood with a solution of carbonate of sodium, Hagenbach (1872) obtained a fluorescent solution. Red Sanders Wood yielded us of ash only 0·8 per cent.

=Commerce=—In the official year 1869-70, Red Sanders Wood produced to the Madras Government a revenue of 26,015 rupees (£2,601). The quantity taken from the forests was reported as 1,161,799 lb.

[784] Gmelin, _Chemistry_, xvi. (1864) 259; the formula assigned to santalic acid (C₁₅H₁₄O₅) appears to be doubtful. Weidel in proposing the formula C₁₄H₁₂O₄ points out that it may be allied to alizarin, C₁₄H₈O₄.

[785] See _Dictionnaire de Chimie_, art. _Santaline_, p. 1434, and for

## particulars: Cazeneuve, _Recherche et extraction des alcaloïdes_, etc.

Paris, 1875. 66. It would appear that the author obtained about 4 per _mille_ of pterocarpin from the wood.

=Uses=—Red Sanders Wood is scarcely employed in pharmacy except for colouring the Compound Tincture of Lavender; but it has numerous uses in the arts. The latter applies also to the wood of _Pterocarpus angolensis_ DC., which is largely exported from the French colony of Gaboon; it is the “Santal rouge d’Afrique of the French,” or Barwood of the English commerce.

BALSAMUM TOLUTANUM.

_Balsam of Tolu_; F. _Baume de Tolu_; G. _Tolubalsam_.

=Botanical Origin=—_Myroxylon Toluifera_ H B K. (_Toluifera Balsamum_ Miller, _Myrospermum toluiferum_ A. Rich.),[786] an elegant and lofty evergreen tree with a straight stem, often as much as 40 to 60 feet from the ground to the first branch. It is a native of Venezuela, and New Granada,—probably also of Ecuador and Brazil.

=History=—The first published account of Balsam of Tolu, is that of the Spanish physician Monardes, who in his treatise on the productions of the West Indies, which in its complete form first appeared at Seville in 1574,[787] relates how the early explorers of South America observed that the Indians collected this drug by making incisions in the trunk of the tree. Below the incisions they affixed shells of a peculiar black wax to receive the balsam, which being collected in a district near Cartagena called _Tolu_, took its name from that place. He adds that it is much esteemed both by Indians and Spaniards, that the latter buy it at a high price, and that they have lately brought it to Spain, where it is considered to be as good as the famous Balsam of Mecca.

Francisco Hernandez, who lived in 1561-1577 in Mexico, stated[788] that the balsam of the province of Tolu was thought to be quite as useful as, if not superior to, “balsamum indicum,” _i.e._ peruvianum.

A specimen agreeing with this description was given to Clusius[789] in 1581 by Morgan, apothecary to Queen Elizabeth, but the drug was certainly not common till a much later period. In the price-list of drugs of the city of Frankfort of 1669, _Balsamus tolutanum_ (sic) is expressly mentioned,[790] but there can be but little doubt that _Balsamum Americanum resinosum_[791] or _siccum_ or _durum_ as occurring in many other tariffs of the 17th century, printed in Germany, was also the balsam under notice;[792] in a similar list emanating from the city of Basle in 1646,[793] we noticed _B. indicum album_, _B. peruvianum_ and _B. siccum_,—the last with the explanatory words, “_trockner Balsam in der Kürbsen_” (_i.e._ in gourds), meaning probably balsam of Tolu.

[786] Fig. in Bentley and Trimen, _Med. Plants_,